The Media Preparation Core Facility provides CCR members and their laboratories with immediate access to a wide variety of culture media and sterile solutions that are critical for their research programs. This includes both standard formulations of bacterial and tissue culture media as well as custom-made yeast medias. The Media Preparation Core Facility also provides specialized media to the Transgenic Animal Core Facility. The media facility is highly reliable, producing a comprehensive panel of reagents that are of outstanding quality and, in many cases, not available from commercial sources. A significant fraction of the facilities operating costs are recovered by per-item chargebacks. The centralization of these services allows the CCR to minimize staff costs and space requirements while maximizing efficiency and cost-effectiveness. Price comparisons with commercial sources (for those items that are commercially available) show that the resulting costs to CCR Investigators are highly competitive. Moreover, outsourcing of these services would preclude us from providing the non-commercially available media that are critical for several of our members. Therefore, the Media Preparation Core Facility is a key resource for CCR researchers and represents excellent value for the CCSG.